Derivatives of pyridoxal



Patented July 13, 1954 UNITED STATES PATENT OFFICE DERIVATIVES FPYRIDOXAL Walter A. Winsten, Forest Hills, N. Y., assignor to FoodResearch Laboratories,

Inc., Long Island City, N. Y., a corporation of New York No Drawing.Application May 26, 1950, Serial No. 164,600

HO CHQOH wherein X stands for COOH, CONHR, and SOZNHR in which Rdesignates a carboxylic acid residue and R designates substituents suchas thiazolyl, diazolyl, pyridyl and the like.

Heyl et a1. (Abstracts, American Chemical Society, 113th meeting,Chicago, 111., April 19, 1948, page 9140) and Snell and Rabinowitz(ibid, page 160) have reported that pyridoxal and amino acids react witheach other to produce Shiff bases; and that these bases may be reducedby hydrogenation using platinum dioxide, PtOz. These workers in this artreported however, that all the pyridoxyl compounds made by them wereinactive for micro-organisms. Heyl et al. have also reported (Jour. Am.Chem. Soc. 70, 16-70 (1948)) on the reactions of pyridoxal with aminessuch as benzylamine, tyramine, tryptamine, histamine, etc., and thecorresponding pyridoxal compounds prepared by the reduction of the Shiifbases so produced. They found that, although the pyridoxylamines so madeby them were active in animals, those amines were not active growthfactors for micro-organisms.

I have discovered that the reduction products obtained uponhydrogenation of the reaction products of pyridoxal andpara-aminobenzoic acid, or related compounds in which an amino group ispositioned para to the acid group (or acid amide group) linked to abenzene nucleus possess, surprisingly, activity for the growth ofmicro-organisms.

This invention therefore has for some of its principal objects theprovision of the novel Shiff bases such as are produced by the reactionof pyridoxal and the acid aromatic para amines or the amides of saidamines, and the provisions of the novel compounds obtained by thereduction of such Shiff bases from the imine state to the amine state.

2 Illustrative examples of this invention are as follows:

Example 1 203 mg. of pyridoxal hydrochloride and 137 mg. of para aminobenzoic acid were dissolved in 5 m1. of methanol. A red precipitatedeveloped which was then filtered. It idene para aminobenzoic acidhaving:

HO CHaOH OOH This Shiff base is poorly soluble in water, but soluble indilute" alkali.

30 mg. of the base were dissolved in 18 ml. of methanol containing 1drop of potassium hydroxide. This solution was then subjected tohydrogenation using 30 mg. of platinic oxide, PtOz, as the catalyst andcarrying out the reduction at a pressure of 1 atmosphere at roomtemperature. When the hydrogenation was completed, the color of theShiif base disappeared.

Paper chromatographic analysis of the product obtained on the reductionof the aforesaid S-hiif base, using .S'accharomyces carlsbergensis,American Type Culture Collection (ATCC) 4228 as the microbial indicator,revealed the presence of a new growth factor together with someunreacted pyridoxal and some pyridoxine.

By using butanol as the developing solvent (method of Winsten and Eigen,Proc. Soc. Exp. Biol. Med, 67, 513 (1948)) it was found that the newgrowth factor moved more slowly than either pyridoxal or pyridoxine.This new growth factor is probably N-pyridoxyl-para amino benzoic acidhaving the formula:

c112 NH HO omoH Example 2 26.6 mg. of benzoylglutamic acid weredissolved in 5 ml. of ethanol, and 20 mg. of potassium hydroxide in 1ml. of 95% ethanol was added thereto. Then 20.3 mg. of pyridoxalhydrochloride was added to the foregoing which resulted in thedevelopment of a yellow color but of cloudy was theN-pyridoxylappearance. Attempts to overcome the cloudiness by addingmore alcohol and heating were without success.

The cloudy material was then subjected to hydrogenation with hydrogenfor one hour, using 30 mg. of platinic oxide, PtOz, at 1 atmosphere atroom temperature.

The reduction product, when subjected to paper chromatographic analysis,showed the presence of 2 new growth factors besides unchanged pyridoxaland pyridoxine observed at the highest level tested. The slowest one maybe an impurity that previously had been observed in pyridoxal itself.The next slowest one is probably N-pyridoxyl-para amino benzoyl glutamicacid having the formula:

OH: NH

HO CHaOH (JO NH l HO O.CH2.CH1.OH.C 0 OH CH2 NH CHa--NB'. nofl omon I OH0 OH 2. N-pyridoxyl-para amino benzoyl glutamic acid having thestructural formula CE:OH H0 H C I \N o IIIH nooocmomoaooon ReferencesCited in the file of this patent UNITED STATES PATENTS Number Name Date2.540.946 Hoffman Feb. 6, 1951

1. PARA-(PYRIDOXYL AMINO) BENZOIC ACID HAVING THE STRUCTURAL FORMULA